Mnemiopsis leidyi:Ecology, Modelling and Observation

What is MEMO?

“MEMO” is the acronym for the project title “Mnemiopsis ecology and modeling: Observation of an invasive comb jelly in the North Sea”. The project is implemented through the partnership between 5 scientific research institutes – ILVO, IFREMER, ULCO-LOG, CEFAS and Deltares – and led by ILVO. The subject of the research is the comb jelly M. leidyi that was observed in the North Sea in 2006. This research project started the 1st January 2011 and is funded by the Interreg IVa MEMO-2 Seas Programme. In total, € 3.5 million is allocated over three years and 20 scientists are involved.

The Interreg IVa MEMO-2 Seas Programme is a unique opportunity to improve and standardize the monitoring of the various partners in this region. This crossborder cooperation will ensure an exchange of expertise on taxonomy (species determination), identification, databases, data analysis and modeling between renowned marine institutes.

Worrying history: invasion in the Black sea and the Caspian sea

The American comb jelly comes from the Atlantic Ocean near the North American coast where it has natural enemies. Presumably it is by ballast water of ships transferred to our region.
The jellyfish measures up to 12cm, although in the North Sea and the English Channel they have been observed to be around 1 to 4 cm. It is a voracious animal that feeds on all kinds of fish larvae, fish eggs and plankton. Mnemiopsis leidyi are capable of self-fertilization, so one copy is sufficient to start the reproductive cycle. The cycle takes about 2 weeks. Mnemiopsis leidyi appears to need little energy and has survived two cold North Sea winters so far.

The invasiveness of the comb jelly M. Leidyi in the Black and Caspian Sea in the 80s and has led to a major change in the marine ecosystem and economic losses due to a decline in fish and shellfish stocks. In 2006 this species was detected in different regions of the 2 Seas area. The spread of M. Leidyi in this area is a major concern because of the presence of important spawning and nursery areas and migration routes for many commercial fish and shellfish. The presence and distribution of M. Leidyi in the 2 Seas region, and it’s interaction with potential prey and predators in relation to possible changes in the environment must be closely monitored to avoid similar disasters like in southern Europe.

MEMO project has a clear and ambitious goal

The project seeks a better understanding of the identification, biology and physiology of the comb jelly, attendance, behavior and impact monitoring in the North Sea and the development of models to assess the ecological and economic impact of M. leidyi in the 2 Seas region.

This will be achieved through three activities:

Development of standard procedures for identification, monitoring and modeling of potential habitat and population dynamics of M. leidyi.

Study of the physiology, eating behavior and potential predators of the species through experiments and mathematical models.

Evaluation of the potential environmental and socio-economic costs of the impact of the species by an ecosystem-based approach.

The ultimate goal is to inform, with the support of the European Union, stakeholders and the general public about the potential risk of M. leidyi on the marine ecosystem and professional activities in the 2 Seas region and to identify possible measures to bring solace to counter this threat.

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